Elastic or semi-elastic structures, such as rope, are used to support a number of structural elements in a wide variety of uses. Some examples are swings, shelves, acrobatic devices and hanging displays. The most common device supported by rope or other elastic or semi-elastic supports are swings, particularly those dedicated for use by children. Techniques for adjusting such swings are well-known and a number of examples are provided below.
French Patent No. 2,501,517 to Hardy discloses a swing for small children having a seat which is suspended from ropes fixed at the top of the rope by jaws pulled together by a spring. An attachment ring for each rope is hung from a hook under each set of jaws. The height of the seat can be adjusted by altering the position of guides on each rope to which the respective ropes are threaded. Pre-installation adjustment is not disclosed.
U.S. Pat. No. 4,304,437 to Longo discloses adjustable chair suspended from a single support point. The chair is biased for the comfort of the user. At the top of the chair are two support members forming an "A" frame. Both are pivotally mounted to the back of the chair at either side. A rope is attached to the front of the bottom of the chair and passes over the apex of the "A" frame to support the bottom of the chair. The base of the chair can be varied by adjusting the length of the rope. Adjustment to the rope as well as any other structure that can be used to adjust the bias of the chair is made after the chair is installed.
U.S. Pat. No. 5,580,317 to Yun discloses a swing which allows the manual elevation of a user's position by use of the users feet or hands. The swing time is increased by the movement of the users hand and feet. The apparatus includes a fixed sitting board attached to the swing ropes and having an arcuate hollow guide pipe, as well as a fixed pipe. Also included is a moveable sitting board coupled to the fixed board, and having an arcuate slide bar engaged with the guide pipe of the fixed board. The moveable sitting board also has a support bar which is pivoted to the fixed pipe of the fixed board by a pivot pin. Pre-installation adjustment is apparently not disclosed.
U.S. Pat. No. 1,066,991 to Broagley discloses a baby swing having a foot-rest which assumes a position beneath the seat while the swing is unoccupied, and automatically projects into an active position when occupied. As a result, the foot-rest is eliminated as an obstruction. As a result, larger children can use the swing by temporarily discarding the foot-rest. These adjustments occur after installation.
U.S. Pat. No. 3,901,165 to Schlesinger discloses a hanging shelf with the leveling device. The shelf has a platform suspended by at least three cords or other flexible suspension structures. The upper ends of the cords are gathered in a knot formed with a loop for suspension from a hook. The lower ends of the cords are attached to the platform. Two of these cords are attached at opposite ends of the side of the platform on one side of the shelf. At the opposite end of the shelf a bead slides over two other ends of the cords to provide leveling adjustment. Other adjustments are apparently carried out after installation of the shelf.
U.S. Pat. No. 5,287,610 to Gomolak et al. discloses a seat assembly work station and a method of operating the work station. The work station is dedicated to adjusting a seating unit. A vertical compressor operates to compress a seat bottom cushion of the seating unit while at the same time permitting rotation of the compressor and the seat pedestal about a common vertical access. This facilitates final installation of the bottom cushion. Further, a second essentially horizontal compressor and a pair of manually operable seat back rest trim cover structures are provided for assisting a worker in the final assembly of the seat back rest trim to the seating unit. There is no indication that the seating unit is suspended from rope or any other semi-elastic structure, or that the back of the seat is adjusted before installation as a hanging unit.
The conventional art discloses no teaching of adjusting the ropes of the swing to a particular swing seat bias before installation of the swing. As a result, tedious adjustments are often necessary to adjust the swing to the correct bias after the swing has been installed. To obtain the correct swing bias by stretching and adjusting the ropes that suspend the swing, the final adjustments of the swing can become very problematical. Consequently, there remains a need for a quick, easy technique for pre-adjusting a swing (including rope stretching and measuring form placement in supports) before installation of the swing.